Johan Oppen

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Oil tanker traffic constitutes a vital part of the maritime operations in the High North and is associated with considerable risk to the environment. As a consequence, the Norwegian Coastal Administration (NCA) administers a number of vessel traffic services (VTS) centers along the Norwegian coast, one of which is located in the town of Vardø, in the(More)
We investigate an optimization problem in container ports, for which previous models based on generalized set partitioning formulations have been studied. We describe two combinatorial relaxations based on computing maximum weighted matchings in suitable graphs. Besides dual bounds, those also provide a variable reduction technique and a matheuristic.(More)
We describe an opportunity to speed up multi-stage scenario generation and reduction using a combination of two well known methods: the moment matching method (Høyland and Wallace 2001) and the method for scenario reduction to approximately minimize a metric (Heitsch and Römish 2009). Our suggestions is to combine them rather than using them in serial by(More)
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